Zarya is definitely weaker than before but not the weakest. Blizzard’s horrendous balancing in season 10 somehow dragged Zarya under the bus too since she was part of the deathball comp that came about and since we all knew season 10 was a terrible mess of bad balancing decisions from Blizzard in order to get rid of dive, we knew the heroes would get nerfed eventually and they did (Brig, Hanzo 2.0, etc) and somehow Zarya got dragged in to the nerf hammer with them.
As a Zarya main, she’s definitely not the worst hero in the game but she’s fallen off quite a bit. I kind of think of Zarya as similar to Bastion or Pharah in some ways, in that if you don’t have the right team around you, it’s going to be very very hard to be effective or get anything out of the game. For example if I don’t have a second tank on the team, I never play Zarya, it’s just fighting an uphill battle, would rather DPS or heal in those situations.